Re: [PATCH v6 21/26] selftests: net/fcnal: Initial tcp_authopt support

From: Eric Dumazet <edumazet@google.com>
To: Leonard Crestez <cdleonard@gmail.com>
Cc: David Ahern <dsahern@kernel.org>,
	Philip Paeps <philip@trouble.is>,
	Dmitry Safonov <0x7f454c46@gmail.com>,
	Shuah Khan <shuah@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	Kuniyuki Iwashima <kuniyu@amazon.co.jp>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
	Jakub Kicinski <kuba@kernel.org>,
	Yuchung Cheng <ycheng@google.com>,
	Francesco Ruggeri <fruggeri@arista.com>,
	Mat Martineau <mathew.j.martineau@linux.intel.com>,
	Christoph Paasch <cpaasch@apple.com>,
	Ivan Delalande <colona@arista.com>,
	Caowangbao <caowangbao@huawei.com>,
	Priyaranjan Jha <priyarjha@google.com>,
	netdev <netdev@vger.kernel.org>,
	"open list:HARDWARE RANDOM NUMBER GENERATOR CORE" 
	<linux-crypto@vger.kernel.org>,
	"open list:KERNEL SELFTEST FRAMEWORK" 
	<linux-kselftest@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 21/26] selftests: net/fcnal: Initial tcp_authopt support
Date: Wed, 27 Jul 2022 11:27:43 +0200	[thread overview]
Message-ID: <CANn89iLUuSWFHbZnb9DSJfR58bCU=pq+uPmT6s45=nrDzMWYYg@mail.gmail.com> (raw)
In-Reply-To: <dd2ca85e-ab29-2973-f129-9afafb405851@gmail.com>

On Wed, Jul 27, 2022 at 10:29 AM Leonard Crestez <cdleonard@gmail.com> wrote:
>
>
> On 7/26/22 10:27, Eric Dumazet wrote:
> > On Tue, Jul 26, 2022 at 9:06 AM Eric Dumazet <edumazet@google.com> wrote:
> >>
> >> On Tue, Jul 26, 2022 at 8:16 AM Leonard Crestez <cdleonard@gmail.com> wrote:
> >>>
> >>> Tests are mostly copied from tcp_md5 with minor changes.
> >>>
> >>> It covers VRF support but only based on binding multiple servers: not
> >>> multiple keys bound to different interfaces.
> >>>
> >>> Also add a specific -t tcp_authopt to run only these tests specifically.
> >>>
> >>
> >> Thanks for the test.
> >>
> >> Could you amend the existing TCP MD5 test to make sure dual sockets
> >> mode is working ?
> >>
> >> Apparently, if we have a dual stack listener socket (AF_INET6),
> >> correct incoming IPV4 SYNs are dropped.
>
> >>   If this is the case, fixing MD5 should happen first ;
>
> I remember looking into this and my conclusion was that ipv4-mapped-ipv6
> is not worth supporting for AO, at least not in the initial version.
>
> Instead I just wrote a test to check that ipv4-mapped-ipv6 fails for AO:
> https://github.com/cdleonard/tcp-authopt-test/blob/main/tcp_authopt_test/test_verify_capture.py#L191
>
> On a closer look it does appear that support existed for
> ipv4-mapped-ipv6 in TCP-MD5 but my test didn't actually exercise it
> correctly so the test had to be fixed.
>
>
> Do you think it makes sense to add support for ipv4-mapped-ipv6 for AO?
> It's not particularly difficult to test, it was skipped due to a lack of
> application use case and to keep the initial series smaller.

I think this makes sense. ipv4-mapped support is definitely used.

>
> Adding support for this later as a separate commit should be fine. Since
> ivp4-mapped-ipv6 addresses shouldn't appear on the wire giving them
> special treatment "later" should raise no compatibility concerns.
>
>
> >> I think that we are very late in the cycle (linux-5.19 should be
> >> released in 5 days), and your patch set should not be merged so late.
>
> This was posted in order to get code reviews, I'm not actually expecting
> inclusion.

To be clear, I am supporting this work and would like to see it being
merged hopefully soon ;)